Coe Angela M, Li Guohong, Andrei Eva Y
Department of Physics and Astronomy, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA.
Rev Sci Instrum. 2024 Aug 1;95(8). doi: 10.1063/5.0212244.
One of the daunting challenges in modern low temperature scanning tunneling microscopy (STM) is the difficulty of combining atomic resolution with cryogen-free cooling. Further functionality needs, such as ultra-high vacuum (UHV), high magnetic field (HF), and compatibility with μm-sized samples, pose additional challenges to an already ambitious build. We present the design, construction, and performance of a cryogen-free, UHV, low temperature, and high magnetic field system for modular STM operation. An internal vibration isolator reduces vibrations in this system, allowing for atomic resolution STM imaging while maintaining a low base temperature of ∼4 K and magnetic fields up to 9 T. Samples and tips can be conditioned in situ utilizing a heating stage, an ion sputtering gun, an e-beam evaporator, a tip treater, and sample exfoliation. In situ sample and tip exchange and alignment are performed in a connected UHV room temperature stage with optical access. Multisite operation without breaking vacuum is enabled by a unique quick-connect STM head design. A novel low-profile vertical transfer mechanism permits transferring the STM between room temperature and the low temperature cryostat.
现代低温扫描隧道显微镜（STM）面临的一项艰巨挑战是难以将原子分辨率与无液氦冷却相结合。进一步的功能需求，如超高真空（UHV）、高磁场（HF）以及与微米级样品的兼容性，给本就雄心勃勃的设备构建带来了额外挑战。我们展示了一种用于模块化STM操作的无液氦、超高真空、低温和高磁场系统的设计、构造及性能。内部振动隔离器减少了该系统中的振动，使得在保持约4 K的低基础温度和高达9 T的磁场的同时能够进行原子分辨率的STM成像。样品和探针可以利用加热台、离子溅射枪、电子束蒸发器、探针处理器和样品剥离器进行原位处理。原位样品和探针的交换与对准在一个具有光学通道的相连超高真空室温平台上进行。独特的快速连接STM头设计实现了不破坏真空的多站点操作。一种新颖的低剖面垂直传输机构允许在室温与低温低温恒温器之间转移STM。
